Determination of 3,4-dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid in human plasma by a simple and rapid high-performance liquid chromatography assay

Plasma levels of 3-methoxy-4-hydroxyphenylglycol levels, number of hospitalization and cognitive function predicts the cognitive effect of atypical antipsychotic monotherapy in patients with acute schizophrenia

Although the effects of atypical antipsychotics with regard to improving neurocognitive function are not sufficiently high. The present study applied an atypical antipsychotic monotherapy for patients with acute schizophrenia to (1) examine the percentage of patients who respond well to this treatment, (2) explore the factors that predict response (e.g. the improvement of neurocognition), and (3) identify the factors associated with improved neurocognitive function. We studied 40 patients with acute schizophrenia who had received atypical antipsychotic monotherapy for 24 weeks. The following parameters were evaluated at baseline and 24 weeks after the start of treatment: psychotic symptoms, neurocognitive function, and blood biological markers including homovanillic acid, 3-methoxy-4-hydroxyphenylglycol, and brain-derived neurotrophic factor. Marked improvements in neurocognitive function were noted in 7.5%-25% of patients. The factors that significantly predicted neurocognitive function improvement were the frequency of hospitalization (verbal memory and verbal fluency), 3-methoxy-4-hydroxyphenylglycol (verbal fluency and executive function), and verbal memory (working memory). Approximately 20% of the patients showed good response to treatment with antipsychotics. Frequency of hospitalization, 3-methoxy-4-hydroxyphenylglycol level, and other parameters predicted responsiveness to these drug therapies. Thus, it might be useful to apply these factors to predict responses to treatment.

Plasma levels of IL-6 in patients with untreated major depressive disorder: comparison with catecholamine metabolites

OBJECTIVE

IL-6 and catecholamines play roles in the pathophysiology of major depressive disorder (MDD).

AIM

The present study investigated associations between plasma IL-6 and plasma catecholamine metabolites in patients with MDD.

PARTICIPANTS AND METHODS

A total of 148 patients (male/female 65/83, age 49.5±12.1 years) who met the criteria for MDD based on the Diagnostic and Statistical Manual of Mental Disorders IV and 40 participants as healthy controls (HC; male/female 23/17, age 44.0±10.5 years) were enrolled in the present study. Plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were analyzed using high-performance liquid chromatography, and plasma IL-6 levels were measured using ELISA.

RESULTS

No correlations were observed among plasma IL-6 levels, MHPG levels, and HVA levels in patients with MDD. Plasma IL-6 levels in patients with MDD were significantly higher than in the HC. A positive correlation was found between plasma IL-6 levels and Hamilton Rating Scale for Depression-17 scores.

CONCLUSION

No correlations existed between plasma IL-6 levels and plasma catecholamine metabolite levels in patients with MDD, and the severity of depressive state was related to plasma IL-6 levels in MDD.

Relationships between serum brain-derived neurotrophic factor, plasma catecholamine metabolites, cytokines, cognitive function and clinical symptoms in Japanese patients with chronic schizophrenia treated with atypical antipsychotic monotherapy

OBJECTIVES

Catecholamines, brain-derived neurotrophic factor (BDNF) and cytokines may be involved in the pathophysiology of schizophrenia. The aim of this study was to examine the associations between serum BDNF levels, plasma catecholamine metablolites, cytokines and the cognitive functions of patients with schizophrenia treated with atypical antipsychotic monotherapy.

METHODS

One hundred and forty-six patients with schizophrenia and 51 age- and sex-matched healthy controls were examined for peripheral biological markers and neurocognitive test.

RESULTS

There were positive correlations between serum BDNF levels and scores for verbal memory and attention and processing speed as well as between serum BDNF levels and negative symptoms. Furthermore, there was a negative correlation between the plasma homovanillic acid (HVA) level and motor function and a positive correlation between the plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) level and attention and processing speed. There were no significant correlations between interleukin-6 or tumour necrosis factor alpha and cognitive function. Moreover, there were no significant correlations between the plasma levels of HVA, MHPG, cytokines and clinical symptoms.

CONCLUSIONS

Serum BDNF levels are positively related to the impairment of verbal memory and attention, plasma HVA levels are positively related to motor function, and plasma MHPG levels are positively related to attention in patients with schizophrenia.

Need for medication to complement catecholamines in smoking cessation of hardcore smokers

Many smokers find it difficult to stop smoking without assistance. The antidepressants bupropion and nortriptyline can aid smoking cessation. The main aim of this study was to understand the pathophysiology of smoking cessation better based on biological backgrounds. We investigated the following biological markers for any alterations during smoking cessation in the absence of pharmacotherapy: the dopamine metabolite homovanillic acid (HVA), the noradrenaline metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) and brain-derived neurotrophic factor (BDNF). Assessment and blood sampling were performed at a baseline (the start) time point and at a critical time point during smoking cessation. Seven of 30 smokers quit during a 16-week follow-up period; these smokers were defined as remission group from tobacco dependence. The remaining 23 smokers were categorized as hardcore smokers. The smoking group was compared with 23 non-smokers matched for age and gender. We compared blood levels of biological markers in each of the three groups. The hardcore smoker group showed significant decreases in HVA and MHPG levels between baseline and the critical time point (p=0.018 and p=0.033, respectively). However, the remission from tobacco dependence group exhibited no significant changes in any of the biomarkers examined. They had lower scores on the Minnesota nicotine withdrawal scale than the hardcore smoker group (p=0.002). The hardcore smoker group had higher MHPG and BDNF levels than the non-smoker group (p=0.002 and p<0.001, respectively). Hardcore smokers experience severe nicotine withdrawal symptoms. Nicotine withdrawal is associated with catecholamine deficiency. The resulting withdrawal symptoms make quitting difficult for hardcore smokers. These hardcore smokers may require medication to compensate for the catecholamine deficit. Non-nicotinic medications such as bupropion, nortriptyline, or varenicline may be required to bolster the catecholamine deficit in hardcore smokers.

Yokukansan improves behavioral and psychological symptoms of dementia by suppressing dopaminergic function

Although three drugs, risperidone, yokukansan, and fluvoxamine, have shown equal efficacy in treating behavioral and psychological symptoms of dementia (BPSD) in our previous study, their mechanisms of action are different from one another. Monoamines have attracted attention for their key roles in mediating several behavioral symptoms or psychological symptoms through synaptic signaling. We aimed to clarify the monoamines changed by treatment with each drug in patients with BPSD. The main purpose of this study was to determine whether plasma levels of catecholamine metabolites are correlated with pharmacological treatments. This was an 8-week, rater-blinded, randomized, flexible-dose, triple-group trial. In total, 90 subjects were recruited and subsequently three different drugs were allocated to 82 inpatients with BPSD. We examined BPSD data from patients who completed 8 weeks of treatment. Eventually, we analyzed 42 patients (yokukansan: 17; risperidone: 9; fluvoxamine: 16). Homovanillic acid, a metabolite of dopamine, and 3-methoxy-4-hydroxyphenylglycol, a metabolite of noradrenaline, in their plasma were analyzed by high-performance liquid chromatography with electrochemical detection. All three drugs showed equal significant efficacy between baseline and study endpoint. By contrast, biomarkers showed mutually different changes. Patients in the yokukansan group had significantly decreased plasma homovanillic acid levels from baseline. Conversely, patients in the risperidone and fluvoxamine groups exhibited no significant changes in plasma homovanillic acid levels from baseline. Yokukansan contains geissoschizine methyl ether, which is known to have a partial agonist effect on dopamine D2 receptors. An improvement in BPSD condition with the intake of yokukansan is suggested to occur through a suppressed dopaminergic function, which is similar to the effect of aripiprazole.

The noradrenaline metabolite MHPG is a candidate biomarker between the depressive, remission, and manic states in bipolar disorder I: two long-term naturalistic case reports

BACKGROUND

Treatment of the depressive and manic states in bipolar disorder I (BDI) is a challenge for psychiatrists. Despite the recognized importance of the switch phenomenon, the precise mechanisms underlying this process are yet to be shown. We conducted a naturalistic study in two BDI patients to determine whether biological markers (monoamine metabolites and brain-derived neurotrophic factor [BDNF]) are associated with the switch between depressive and manic states.

CASE PRESENTATION AND METHODS

Blood sampling and mood assessments were performed at 2-week intervals over a period of 2 (Case 1, n=72) and 6 (Case 2, n=183) years. Plasma concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were analyzed by high-performance liquid chromatography with electrochemical detection. Plasma BDNF was assayed by sandwich ELISA (enzyme-linked immunosorbent assay).

RESULTS

MHPG had the highest standardized coefficient (β) in the multiple regression analysis. We found a significant positive correlation between Young Mania Rating Scale scores and plasma MHPG levels (Case 1: ρ=0.429; Case 2: ρ=0.488), and a significant negative correlation between Montgomery-Asberg Depression Rating Scale scores and MHPG levels (Case 1: ρ=-0.542; Case 2: ρ=-0.465). Conversely, no significant correlation was found between the level of BDNF and the presence of a manic or depressive state, and although HVA had a slightly stronger correlation than MHPG, the levels of neither of these were found to significantly correlate with the symptoms.

CONCLUSION

These data suggest that peripheral MHPG levels (which is related to noradrenaline levels in the brain) could be used as a biomarker of mood states in BDI. The noradrenaline level in the brain is likely to reflect the clinical characteristics of the switch process in BDI, and has prognostic significance for the treatment of both manic and depressive states.

Catechol-O-methyltransferase Val158Met genotype and the clinical responses to duloxetine treatment or plasma levels of 3-methoxy-4-hydroxyphenylglycol and homovanillic acid in Japanese patients with major depressive disorder

PURPOSE

This study investigated the relationships among the plasma levels of catecholamine metabolites, the clinical response to duloxetine treatment, and Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene.

SUBJECTS AND METHODS

Sixty-four patients and 30 healthy control subjects were recruited. Major depressive episodes were diagnosed using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. The severity of depression was evaluated using the 17-item Hamilton Rating Scale for Depression (HAMD17). Patients whose HAMD17 scores were 15 or greater were enrolled in the study. Blood sampling and clinical evaluation were performed at week 0 and week 8. The levels of plasma catecholamine metabolites were measured using high-performance liquid chromatography with electrochemical detection. Genotyping was performed using direct sequencing.

RESULTS

Thirty of 45 patients (67%) responded to duloxetine treatment during the 8 weeks of treatment. The baseline plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG), but not homovanillic acid (HVA), were lower in patients with major depressive disorder (MDD) who had the Val/Val genotype than in patients who were Met-carriers. Patients with MDD and the Val/Val genotype, but not Met carriers, had increased plasma levels of MHPG after 8 weeks of duloxetine treatment. The baseline plasma MHPG levels in healthy control subjects with the Val/Val genotype were significantly higher than those in patients with MDD. Among the subjects in the MDD group with the Val/Val genotype, the plasma MHPG levels increased to the same degree as in the healthy control subjects with the Val/Val genotype after 8 weeks of duloxetine treatment.

CONCLUSION

The relationship among the COMT Val158Met polymorphism, plasma levels of catecholamine metabolites, and responses to duloxetine is complex. Nevertheless, our results suggest that patients with MDD and the Val/Val genotype are more sensitive to the influence of noradrenergic neurons by duloxetine treatment.

The noradrenaline metabolite MHPG is a candidate biomarker from the manic to the remission state in bipolar disorder I: a clinical naturalistic study

Remission is the primary goal of treatment for bipolar disorder I (BDI). Metabolites of noradrenaline and dopamine, 3-methoxy-4-hydroxyphenylglycol (MHPG) and homovanillic acid (HVA), respectively, are reduced by treatment with antipsychotics, but whether these phenomena are caused by antipsychotics or by the pathophysiology of BDI is not known. Interactions between brain-derived neurotrophic factor (BDNF) and mood disorders have also been suggested. We conducted a multifaceted study in BDI patients to ascertain if biological markers are associated with the manic state. Patients with Young Mania Rating Scale (YMRS) scores >20 participated in the study. Final analyses involved 24 BDI patients (13 men and 11 women). We used YMRS scores to identify mania stages in individual BDI patients (i.e., manic syndrome, response and remission stages). Statistical analyses were done using one-way repeated-measures analyses of variance (rep-ANOVA) throughout manic syndrome, response and remission stages. Plasma concentrations of MHPG and HVA were analyzed by high-performance liquid chromatography with electrochemical detection. Plasma levels of BDNF were measured by sandwich enzyme-linked immunosorbent assay. BDI patients had significantly reduced plasma levels of MHPG throughout manic syndrome, response and remission stages (rep-ANOVA, p = 0.002). Without a case of response state, there was a significant positive correlation between YMRS scores and plasma levels of MHPG (ρ = 0.33, p = 0.033, n = 48). Plasma levels of HVA and BDNF were not significantly altered throughout manic syndrome, response and remission stages. These data suggest that the peripheral level of MHPG (which is associated with noradrenaline levels in the brain) could be used as a biomarker for the manic state in BDI. The MHPG level is likely to reflect the clinical characteristics of the manic syndrome in BDI, and noradrenaline may reflect the pathophysiology from manic to remission states.

Comparison of lithium, aripiprazole and olanzapine as augmentation to paroxetine for inpatients with major depressive disorder

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are considered first-line treatments for major depressive disorders (MDD). It has been reported, however, that 30-40% of patients with MDD who received SSRIs failed to respond to treatment. Use of lithium (Li) to augment SSRIs seems to be the most common strategy in such cases. It was recently demonstrated that atypical antipsychotics are effective augmentation agents in MDD. Here, we present a randomized controlled study that compared augmentation with Li, olanzapine (OLA) or aripiprazole (ARI) in paroxetine-refractory patients with MDD.

METHODS

Participants were 30 patients who met Diagnostic and Statistical Manual of Mental Disorders IV criteria for MDD and refractory to paroxetine treatment. Treatment with Li, OLA or ARI was added to paroxetine in a randomized protocol for 4 weeks. We defined the patients whose scores on the Hamilton Rating Scale for Depression decreased 50% or more as responders.

RESULTS

Two patients dropped out because of adverse effects. Response rates to Li, OLA or ARI augmentation were 4/10 (40%), 3/10 (30%) and 4/10 (40%), respectively. In addition, Li, OLA and ARI did not influence plasma paroxetine concentrations.

CONCLUSIONS

We concluded that OLA or ARI could be used as alternatives to Li as options for patients who do not respond to paroxetine treatment.

COMT Val158Met, but not BDNF Val66Met, is associated with white matter abnormalities of the temporal lobe in patients with first-episode, treatment-naïve major depressive disorder: a diffusion tensor imaging study

We investigated the association between the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene, and white matter changes in patients with major depressive disorder (MDD) and healthy subjects using diffusion tensor imaging (DTI). We studied 30 patients with MDD (17 males and 13 females, with mean age ± standard deviation [SD] =44±12 years) and 30 sex- and age-matched healthy controls (17 males and 13 females, aged 44±13 years). Using DTI analysis with a tract-based spatial statistics (TBSS) approach, we investigated the differences in fractional anisotropy, radial diffusivity, and axial diffusivity distribution among the three groups (patients with the COMT gene Val158Met, those with the BDNF gene Val66Met, and the healthy subjects). In a voxel-wise-based group comparison, we found significant decreases in fractional anisotropy and axial diffusivity within the temporal lobe white matter in the Met-carriers with MDD compared with the controls (P<0.05). No correlations in fractional anisotropy, axial diffusivity, or radial diffusivity were observed between the MDD patients and the controls, either among those with the BDNF Val/Val genotype or among the BDNF Met-carriers. These results suggest an association between the COMT gene Val158Met and the white matter abnormalities found in the temporal lobe of patients with MDD.

Serum levels of brain-derived neurotrophic factor (BDNF), BDNF gene Val66Met polymorphism, or plasma catecholamine metabolites, and response to mirtazapine in Japanese patients with major depressive disorder (MDD)

OBJECT

We investigated an association between the polymorphism of brain-derived neurotrophic factor (BDNF) gene Val66Met and the response to mirtazapine in Japanese patients with major depressive disorder (MDD). We also examined mirtazapine's effects on the serum BDNF and plasma levels of catecholamine metabolites in these patients.

METHODS

Eighty-four patients who met the DSM-IV-TR criteria for MDD were treated with only mirtazapine for 4 weeks. The BDNF Val66Met polymorphism was detected by direct sequencing in the region, and serum BDNF levels and plasma levels of catecholamine metabolites were measured by ELISA and HPLC-ECD, respectively.

RESULTS

Mirtazapine treatment for 4 weeks significantly increased serum BDNF levels in the responders, whereas nonresponders showed significant decreases. No association was found between either of the two genotypes (Val/Val vs. Met-carriers) and the response to mirtazapine at T4 or the serum BDNF levels at T0. Mirtazapine did not alter the plasma levels of homovanillic acid (HVA) or 3-methoxy-4-hydroxyphenylglycol (MHPG). Discussion The dynamics of serum BDNF levels, but not plasma levels of HVA and MHPG, reflect the response to mirtazapine treatment; the BDNF Val66Met polymorphism in patients with depression is, however, associated with neither a particular response to mirtazapine treatment nor baseline serum BDNF levels.

CONCLUSION

Serum BDNF levels, but not plasma levels of HVA or MHPG, and BDNF Val66Met polymorphism are related to the mirtazapine response in MDD.

Plasma levels of metabolites of catecholamine in nicotine-dependent patients treated with varenicline

INTRODUCTION

Our hypothesis is that varenicline decreases the plasma levels of catecholamine metabolites; such a decrease is associated with the main mechanisms of smoking cessation and leads to a depressive state. To confirm the hypothesis, we investigated the association of plasma homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in patients with nicotine dependence in comparison with nonsmokers.

METHODS

To confirm the hypothesis, we investigated the association of plasma HVA and MHPG levels in patients with nicotine dependence in comparison with nonsmokers. In addition, we also examined the plasma HVA and MHPG levels before (T0) and 8 weeks after the varenicline treatment (T8).

RESULTS

Seventeen of 20 smokers (85.0%) stopped smoking during the 12 weeks of treatment. Plasma HVA levels and MHPG levels in the patients at T0 (HVA 5.1 ± 2.1 ng/ml, MHPG 2.2 ± 0.6 ng/ml) were significantly higher than those of the control group (HVA 3.0 ± 1.0 ng/ml, MHPG 1.6 ± 1.4 ng/ml; HVA p = .0012, MHPG p = .0069). In this study, the plasma HVA and MHPG levels were not changed after treatment with varenicline, although the smokers had already quit.

CONCLUSIONS

These results suggest that varenicline sustains higher catecholamine levels. The findings that the treatment with varenicline did not decrease the plasma levels of catecholamine metabolites can explain why none of the smokers had become depressed after the varenicline treatment.

Comparison of brain N-acetylaspartate levels and serum brain-derived neurotrophic factor (BDNF) levels between patients with first-episode schizophrenia psychosis and healthy controls

BACKGROUND

N-acetylaspartate (NAA) levels and serum brain-derived neurotrophic factor (BDNF) levels in patients with first-episode schizophrenia psychosis and age- and sex-matched healthy control subjects were investigated. In addition, plasma levels of homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were compared between the two groups.

METHOD

Eighteen patients (nine males, nine females; age range: 13-52 years) were enrolled in the study, and 18 volunteers (nine males, nine females; age range: 15-49 years) with no current or past psychiatric history were also studied by magnetic resonance spectroscopy (MRS) as sex- and age-matched controls.

RESULTS

Levels of NAA/Cr in the left basal ganglia (p=0.0065) and parieto-occipital lobe (p=0.00498), but not in the frontal lobe, were significantly lower in patients with first-episode schizophrenia psychosis than in control subjects. No difference was observed between the serum BDNF levels of patients with first-episode schizophrenia psychosis and control subjects. In regard to the plasma levels of catecholamine metabolites, plasma MHPG, but not HVA, was significantly lower in the patients with first-episode psychosis than in control subjects. In addition, a significantly positive correlation was observed between the levels of NAA/Cr of the left basal ganglia and plasma MHPG in all subjects.

CONCLUSION

These results suggest that brain NAA levels in the left basal ganglia and plasma MHPG levels were significantly reduced at the first episode of schizophrenia psychosis, indicating that neurodegeneration via noradrenergic neurons might be associated with the initial progression of the disease.

Predictive factors for responding to sertraline treatment: views from plasma catecholamine metabolites and serotonin transporter polymorphism

In the present study, we investigated the effects of sertraline on plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and serum brain-derived neurotrophic factor (BDNF) levels in 59 depressed patients treated with sertraline. We also examined the relationship between the dynamics of the catecholamine metabolites, BDNF, serotonin transporter-linked polymorphic region (5-HTTLPR) gene polymorphism (long and short alleles), and the clinical response to sertraline. The extent of clinical improvement was evaluated using the 17-item Hamilton Rating Scale for Depression (Ham-D) before and 8 weeks after treatment with sertraline. Responders were defined as showing at least a 50% decrease in the Ham-D score. Baseline plasma HVA levels of responders to sertraline treatment were significantly lower than those of non-responders (p = 0.02). In addition, a positive correlation was identified between changes in plasma HVA levels and the rate of response to sertraline treatment (p = 0.001). A trend toward higher baseline serum BDNF levels was found in responders compared with non-responders (p = 0.095). In addition, serum BDNF levels were slightly increased (not significant) in responders (p = 0.058), but not in non-responders. Responders had a higher short-allele genotype frequency in the 5-HTTLPR for the promoter region than did non-responders (p = 0.037). These results suggest that pre-treatment plasma HVA levels and the 5-HTTLPR genotype for the promoter might be associated with a response to sertraline.

Different patterns of longitudinal changes in plasma levels of catecholamine metabolites and brain-derived neurotrophic factor after administration of atypical antipsychotics in first episode untreated schizophrenic patients

In the present study, we longitudinally investigated the effects of risperidone, olanzapine, and aripiprazole on plasma levels of catecholamine metabolites and brain-derived neurotrophic factor (BDNF) in first-episode unmedicated schizophrenic patients. The subjects were 59 Japanese schizophrenic patients (35 males and 24 females; age range: 18-46 years; mean+/-SD: 25+/-16 years). The patients were treated with risperidone (n=32) in a dose range of 2-6 mg/day (mean+/-SD=3.4+/-1.9), olanzapine (n=18) in a dose range of 5-20 mg/day (mean+/-SD=12.1+/-5.8), or aripiprazole (n=9) in a dose range of 12-30 mg/day (mean+/-SD=22.8+/-10.1). All three drugs significantly decreased plasma homovanillic acid (HVA) levels within 8 weeks, although aripiprazole transiently raised this level before 8 weeks. All three drugs also significantly increased plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels within 8 weeks. On the other hand, none of them altered plasma BDNF levels. These results indicate that risperidone, olanzapine, and aripiprazole affect catecholaminergic systems in the brain, that the effects of aripiprazole on the dopaminergic systems seem to slightly different than those of risperidone and olanzapine, and that these atypical antipsychotic drugs might not alter BDNF levels, at least within 8 weeks of treatment.

Associations between plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) and negative symptoms or cognitive impairments in early-stage schizophrenia

Schizophrenic patients demonstrate a variety of cognitive deficits, including attention, executive functions, and working memory, even in the early stage of disease. In the present study, we examined the association between blood levels of 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), or brain-derived neurotrophic factor (BDNF) and scores on the Wisconsin Card Sorting Test (WCST) in patients with early-stage schizophrenia. We also investigated the association between frontal GABA levels using 1H-magnetic resonance spectroscopy (MRS) at 3T and scores on the WCST in the same patients. Blood levels of BDNF and catecholamine metabolites and brain GABA levels using 1H-MRS were measured in 18 schizophrenic patients (nine males, nine females; age range 13-52 year). A significantly positive correlation was observed between plasma MHPG levels and %PEM (rho = -0.686, p = 0.0047). A trend toward negative correlation was found between frontal lobe GABA levels and the per cent of preservation error (%PEM) in the early stage of schizophrenia (rho = -0.420, p = 0.0836). These results suggest that noradrenergic neurons might be involved in neuropsychological functions in early-stage of schizophrenia.

Efficacy of electroconvulsive therapy is associated with changing blood levels of homovanillic acid and brain-derived neurotrophic factor (BDNF) in refractory depressed patients: a pilot study

Electroconvulsive therapy (ECT) is effective for patients with antidepressant medication-resistant depression. However, the mechanisms of ECT's effectiveness for treating depression are not fully understood. We therefore investigated ECT's effects on blood levels of brain-derived neurotrophic factor (BDNF), catecholamine metabolites, and nitric oxide (NO) in 18 treatment-refractory depressed patients. Serum BDNF levels increased significantly following ECT in responders to ECT (before ECT: 8.0+/-9.7 ng/mL; five weeks after start of ECT: 15.1+/-11.1 ng/mL), whereas BDNF levels in non-responders were unchanged (before ECT: 11.5+/-11.0 ng/mL; five weeks after start of ECT: 9.4+/-7.5 ng/mL). Furthermore, the plasma HVA levels, but not MHPG levels, were significantly reduced after ECT (before ECT: 8.5+/-1.9 ng/mL; five weeks after start of ECT: 5.8+/-2.2 ng/mL). This latter finding occurred in parallel with the improvement of depressive symptoms in all patients. These results suggest that the mechanisms underlying ECT's effect on refractory depression may be related to dopaminergic neurons and BDNF.

Effects of acute paroxetine treatment on the consumption of cigarette smoking and caffeine in depressed patients

In the present study, we examined the effects of acute treatment with paroxetine on the consumption of cigarette smoking and caffeine in 65 patients who met the DSM-IV criteria for major depressive disorder (M/F: 28/37, age: 48 +/- 15 years). Plasma levels of cotinine or caffeine were analysed using high-performance liquid chromatography (HPLC). The amount of cigarette smoking and plasma levels of cotinine, but not caffeine, decreased 4 weeks after paroxetine treatment. There was no difference between smokers and nonsmokers with respect to their response to paroxetine treatment. In addition, plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in responders to paroxetine treatment was higher than those in nonresponders, and there was a negative correlation between the changes in plasma MHPG levels and the changes in Hamilton rating scale for depression (Ham-D) scores before and 4 weeks after paroxetine administration. These results suggest that paroxetine has the potential to reduce the amount of cigarette smoking in depressed smokers, and we reconfirmed our previous results that depressed patients with higher plasma MHPG levels had better response to paroxetine treatment than those with lower plasma MHPG levels using larger depressed samples.

Risperidone in the treatment of psychotic depression

In the preset study, the authors investigated that effects of the antipsychotic drug risperidone on psychotic depression and examined the mechanism of risperidone to ameliorate psychotic depression. Fifteen patients met the DSM-IV criteria for major depressive disorder with psychotic features and the remaining five patients met those for bipolar I disorder (most recent episode depressed) with psychotic features (M/F: 8/12, age: 54+/-18). All patients were evaluated regarding their clinical improvement using the Hamilton Rating Scale for Depression (Ham-D), and Positive and Negative Syndrome Scale (PANSS). In addition, plasma concentrations of HVA and MHPG were analyzed by HPLC. Patients with a 50% or more improvement in Ham-D score were defined as responders. Three were prescribed risperidone alone, and the other 17 were administered risperidone as an addition to preexisting antidepressants or mood stabilizers. The preexisting antidepressants or mood stabilizers were as follows: paroxetine (6), lithium (3), valproic acid (3), clomipramine (2), fluvoxamine (1), amitriptyline (1), amoxapine (1). The average dose of risperidone was 1.8+/-0.5 mg/day. Eleven of twenty patients (55%) turned out to be responders 4 weeks after initiation of risperidone administration. No differences were observed between responders and nonresponders with respect to age, sex, Ham-D score before risperidone treatment, dose and plasma level of risperidone or its active metabolite, 9-hydroxyrisperidone. Plasma HVA levels before risperidone administration in responders were significantly higher than those in nonresponders. In addition, a significant correlation was observed between changes in plasma HVA level and the percentage improvement on Ham-D score. These results indicate that treatment with risperidone is effective to ameliorate psychotic depression, and the influence of risperidone on dopaminergic activity is associated with its efficacy.

An open study of risperidone liquid in the acute phase of schizophrenia

An open-label study was performed to investigate the clinical efficacy and mechanisms of risperidone liquid in ameliorating positive symptoms in the acute phase of schizophrenia. Eighty-eight patients (M/F: 50/38; age: 18-74 years;, mean +/- SD =32 +/- 16 years) meeting DSM-IV criteria for schizophrenia and treated with risperidone liquid (14 patients also used lorazepam) were evaluated with regard to their clinical improvement and extrapyramidal side effects using the positive and negative syndrome scale (PANSS) and the Simpson and Angus scale (SAS), while plasma concentrations of HVA and MHPG were analysed by HPLC-ECD before and 4 weeks after risperidone liquid administration. Patients showing a 50% or greater improvement in PANSS scores were defined as responders. An improvement in the PANSS scores related to excitement, hostility and poor impulse control was seen within 7 days after administration of risperidone liquid, and an improvement with regard to hallucinatory behaviour and uncooperativeness was seen within 14 days after its administration. Finally, 68% of patients were classified as responders 4 weeks after risperidone liquid administration. The scores of SAS were not changed after risperidone liquid administration. Pretreatment plasma homovanillic acid (HVA) levels in the responders (8.1 +/- 2.9 ng/ml) were higher than those in nonresponders (5.9 +/- 1.9 ng/ml). In addition, a negative correlation was seen between the changes in plasma HVA levels and the percentage of improvement in PANSS scores. On the other hand, there were no differences between pretreatment plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels and those of nonresponders. These results suggest that risperidone liquid is effective and well tolerated for the treatment of acute phase schizophrenic patients, and that efficacy is related to its affects on dopaminergic activity, not noradrenergic activity.

Prediction of response to risperidone treatment with respect to plasma concencentrations of risperidone, catecholamine metabolites, and polymorphism of cytochrome P450 2D6

In the present study, we examined the relationships between plasma concentrations of risperidone and clinical responses, extrapyramidal symptoms, plasma levels of cotinine and caffeine, or cytochrome (cyp)2D6 genotypes. In addition, we also investigated the relationships between plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) or homovanillic (HVA) acid and clinical responses to risperidone. One hundred and 36 patients (male/female: 58/78, age 37+/-13 years) who met DSM-IV criteria for schizophrenia, schizoaffective disorder, delusional disorder and brief psychotic disorder, and who were being treated with risperidone alone, were evaluated regarding their clinical improvement and extrapyramidal symptoms using the Positive and Negative Syndrome Scale (PANSS) and Simpson and Angus (SAS), respectively, and plasma levels of cotinine, caffeine, MHPG and HVA were analysed by high-performance liquid chromatography. The cyp2D6*5 and *10 alleles were identified using the polymerase chain reaction. There was a positive correlation between plasma levels of risperidone plus 9-hydroxyrisperidone (active moiety) and SAS scores, but not the PANSS. Pretreatment HVA levels in responders were higher than those in nonresponders. In addition, there was a negative correlation between changes in HVA levels and improvement in PANSS scores. There was no association between plasma levels of risperidone and plasma levels of cotinine or caffeine. Furthermore, there were no differences in the risperidone/9-hydroxyrisperidone ratio, clinical improvements and extrapyramidal symptoms among cyp2D6 genotypes. These results indicate that pretreatment HVA levels and plasma concentrations of active moiety might play a part in predicting the clinical response and occurrence of extrapyramidal symptoms, respectively, when treating patients with risperidone.

Plasma levels of homovanillic acid and the response to risperidone in first episode untreated acute schizophrenia

We have previously reported that risperidone might improve negative symptoms in schizophrenia by influencing noradrenergic neurons. In the present study, we focused on the clinical efficacy and mechanisms of risperidone towards positive symptoms in the acute phase of schizophrenia. Thirty-four patients meeting DSM-IV criteria for schizophrenia and treated with risperidone alone were evaluated regarding their clinical improvement using the Positive and Negative Syndrome Scale (PANSS) before and 2 weeks after risperidone administration, and blood samples were also drawn at the same times. Plasma concentrations of homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol were analysed by high-performance liquid chromatography with electrochemical detection. Plasma HVA levels in the responders to the risperidone treatment (more than 50% improvement in scores of positive symptoms in PANSS) were higher than those of non-responders before risperidone administration. Furthermore, there was a negative trend between changes in plasma HVA levels and improvement of total scores for positive symptoms in PANSS. These results suggest that higher levels of plasma HVA before risperidone administration might be a predictor of a good response to risperidone treatment, and the influence of risperidone on dopaminergic activity might be associated with its efficacy in treating symptoms of schizophrenia in the acute phase.

Measurement of plasma 5-hydroxyindoleacetic acid as a possible clinical surrogate marker for the action of antivascular agents

BACKGROUND

Serotonin (5HT), a naturally occurring vasoactive substance, is released from platelets into plasma under various pathological conditions. Recently, anticancer drugs that act by selectively disrupting tumour blood flow have been found to increase plasma 5HT concentrations in mice. Two such antivascular agents, flavone acetic acid (FAA) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA), have completed Phase I clinical trial and raise the important question of whether suitable surrogate markers for antivascular effects can be identified.

METHODS

5HT is unstable to storage, precluding routine clinical assay, but the 5HT metabolite, 5-hydroxyindoleacetic acid (5HIAA) accumulates in plasma following 5HT release and is a more suitable marker because of its greater stability. We have developed an automated procedure for the assay of the low concentrations of 5HIAA found in humans by combining solid-phase extraction with high-performance liquid chromatography (HPLC).

RESULTS

Efficient separation of 5HIAA from possible interfering substances in human plasma, including a variety of pharmaceutical agents, was achieved on C18 columns using cetyltrimethylammonium bromide (CETAB) as an organic modifier. Adequate precision, accuracy and sensitivity were achieved by electrochemical detection (ECD) at +400 mV. Analysis of plasma from two patients treated with DMXAA in a Phase I trial demonstrated DMXAA-induced elevation of plasma 5HIAA with a time course similar to that previously described in mice.

CONCLUSIONS

Measurement of changes in plasma 5HIAA provides a new approach to the monitoring of therapies with an antivascular effect. The assay is sensitive to dietary sources of 5HT, which should be minimised.

Characteristics of fluvoxamine-induced nausea

We investigated the association between fluvoxamine and nausea from various viewpoints. The incidence of nausea induced by fluvoxamine was 29% (12/41). Plasma 5-hydroxyindoleacetic acid (p5-HIAA) levels after fluvoxamine administration were significantly higher in patients with nausea (6.6+/-3.4 ng/ml) than in those without nausea (3.5+/-2.7 ng/ml). On the other hand, no significant differences were found between patients with and patients without nausea in terms of sex, age, initial and maximum dosages of fluvoxamine and its plasma concentrations, and clinical response to fluvoxamine. However, the incidence of nausea in patients who were initially administered fluvoxamine at under 50 mg/day was significantly lower than in those who were started at above 50 mg/day. In addition, mosapride, a member of the benzamide family, was effective in alleviating fluvoxamine-induced nausea. These results suggest that fluvoxamine-induced nausea is associated with hyperactivity in serotonergic neurons.

Effect of clonazepam treatment on antipsychotic drug-induced Meige syndrome and changes in plasma levels of GABA, HVA, and MHPG during treatment

We demonstrated the effect of clonazepam (2 mg/day) on Meige syndrome in two schizophrenic patients under continuous treatment with antipsychotic drugs, and changes in the plasma levels of gamma-aminobutyric acid (GABA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in these cases. The plasma levels of HVA and MHPG during treatment with clonazepam were decreased in the responder, while not changed in the non-responder to clonazepam. A difference between the responder and the non-responder was not found in the plasma GABA levels. These results suggest that hyperactivities of the central dopaminergic and noradrenergic neurones are involved in the pathophysiology of Meige syndrome.

Changes in plasma monoamine metabolites during acute lithium intoxication

A case of acute lithium intoxication is presented in which plasma levels of 3-methyoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxyindoleacetic acid (5-HIAA), and homovanillic acid (HVA) were longitudinally measured during the intoxication period. Plasma levels of MHPH and 5-HIAA, but not HVA were increased during the intoxication period. These results suggest that toxic levels of lithium concentration occurred due to transient enhancement of serotonin and noradrenaline function. Dopamine function was not affected. Copyright 2000 John Wiley & Sons, Ltd.

A simple high-performance liquid chromatography assay for simultaneous measurement of adenosine, guanosine, and the oxypurine metabolites in plasma

To study the effect of pharmacologic agents on the biologic fate of adenosine, a reversed-phase high-performance liquid chromatography (HPLC) assay coupled with a solid-phase extraction (SPE) method was developed for simultaneous determination of plasma adenosine, hypoxanthine, xanthine, inosine, guanosine, and uric acid. The HPLC system consisted of a reversed phase C18 column, UV detector set at 254 nm, and a mobile phase composed of 0.01 M ammonium phosphate: methanol (9.5 : 0.5) vol/vol with the final pH adjusted to 3.9. The standard curves were linear between 0.1-2 microg/mL for all the analytes (except uric acid 50-400 microg/mL), with r2 > 0.99. The absolute recoveries were >60% and accuracy >85% in almost all cases. The limit of detection was <1 ng based on absolute injection of the analytes. The intraassay variations were <10% and interassay variations <15%. The presence of a wide range of medications in plasma samples did not interfere with the assay. The assay was applied successfully to measure plasma adenosine and the oxypurine metabolites in humans and rats. It was noted that plasma concentrations of adenosine and the oxypurine metabolites can vary considerably depending on the method of blood sample collection, and that species differences are apparent.

A simple high-performance liquid chromatography assay for simultaneous determination of plasma norepinephrine, epinephrine, dopamine and 3,4-dihydroxyphenyl acetic acid

A reversed-phase HPLC assay coupled with electrochemical detection for simultaneously measuring plasma levels of norepinephrine, epinephrine, dopamine, and 3,4-dihydroxyphenylacetic acid (DOPAC) was developed. Separation of the catecholamines and the internal standard isoproterenol was obtained by a mobile phase consisting of 7% methanol in 0.1 M citrate buffer containing 0.3 mM sodium ethylenediaminetetraacetic acid (EDTA), and 0.5 mM 1-octanesulfonic acid, operated under isocratic condition at a flow rate of 1.2 ml/min. The potential of the guard cell was set at +650 mV, the first electrode of the analytical cell at +100 mV and the second at + 350 mV. Using a signal-to-noise ratio of > 3, the minimum detection limit assessed by direct on column injection was < 10 pg for analyte. The assays were linear from basal concentrations to 400 ng/ml. The intra- and inter-assay variations were < 10 and 15%, respectively. The assay has been applied successfully to measure plasma concentrations of these catecholamines in humans, rabbits and rats.